I only use Mettler thread because my Bernina does not seem to like others. I finished a spool of thread about half-way through this afternoon and started a new spool, so I don't think it's the thread. I am using the average spool size on the horizontal spool holder. Should I maybe try the vertical? I am using a size 90/14 needle - should I try another size - if so, what size? Thanks for trying to help me. I just can't figure out what I'm doing wrong. - Cynthia